TY - BOOK AU - Sackett,David L. AU - Haynes,R.Brian AU - Tugwell,Peter TI - Clinical epidemiology: a basic science for clinical medicine SN - 0316765953 (pbk.) U1 - 614.4 PY - 1985/// CY - Boston PB - Little, Brown KW - Epidemiologia clĂ­nica ER -